1. Field of the Invention
This invention relates to a compact, great aperture ratio telephoto lens having an angle of view 18.degree.-24.degree., an aperture ratio 1:2.8 and a telephoto ratio 0.92-0.94.
2. Description of the Prior Art
In a lens of this class, when the compactness of the lens has been contemplated, the spherical aberration particularly on the short wavelength side (for example, near g-line) has been remarkably over-corrected to cause deterioration of the performance of the lens during the open condition thereof, so that the lens has not been fit for practical use. To avoid this, it has been necessary to provide a joined surface on a concave lens which is a third lens, as disclosed in Japanese Patent Publication No. 36777/1978, for example.